/Engine/Plugins/Runtime/ChunkDownloader/Source/Public/ChunkDownloader.h
Download (Cache) all pak files in these chunks then fire the callback (convenience wrapper managing multiple DownloadChunk calls)
void DownloadChunks ( const [TArray](API\Runtime\Core\Containers\TArray)< int32 > & ChunkIds, const [FCallback](API\Plugins\ChunkDownloader\FChunkDownloader\FCallback) & Callback, int32 Priority )